An important aspect of achieving visually convincing images in computer graphics is the display of shadows in three-dimensional (3D) scenes. For hardware rendering, i.e., the rasterization of primitives using graphics hardware, two common standard methods are available: shadow mapping and stencil shadow volumes. (See, e.g., some of the patent applications and patents noted above by way of background incorporated by reference herein.) Each of these techniques has its advantages and drawbacks. Important among these is that shadow maps make creating soft shadows relatively easy, but suffer from aliasing problems, particularly in large scenes. Shadow volumes are rendered with pixel accuracy, but it is more difficult to handle light sources that are not perfect point lights or directional lights, and they require a certain quality of the meshes.
It would be desirable to provide new methods, systems, arrangements, and computer program products operable to make shadow volumes more general with respect to the meshes that can serve as occluding geometry, as well as for accelerating the technique, particularly for large and complex input scenes.